This invention relates to tools for installing wheel weights at optimum circumferential locations in the balancing process for vehicular, pneumatic automobile and truck tires. Present computerized wheel balancing apparatus generally requires an operator to install various sized weights, from as large as three ounces to as small as one-fourth ounce, at a number of determined locations around the tire to achieve accurate balancing. The present method of installation requires the operator to grasp such weight between thumb and forefinger, place it at the designated location, and mount it to the rim by hitting it with a weight hammer. This process is labor intensive, even when using the most sophisticated computerized positioning equipment, time consuming, and often is painful to the person installing these weights.
Impact tools are known for various uses. A nail holding and driving tool is disclosed, for example, in U.S. Pat. No. 6,036,073 and in other prior art references cited in the disclosure statement submitted or to be submitted with this application. Impact tools for cracking ice are known (U.S. Pat No. 6,009,626), for breaking glass (U.S. Pat No. 5,791,056), and for chopping various materials (U.S. Pat. No. 4,458,415). Magnetic chucks are also known for holding various workpieces, such as screws held by magnetic screwdrivers and tin lids held by magnetic can openers. U.S. Pat. No. 4,610,188 discloses a tool for driving metallic fasteners, which tool includes a magnetic driving head used with pneumatic power hammers and includes an integrally formed shank having a mounting or base portion and a driving head.
Although tire balancing using steel or lead weights has been employed for a very long time, see, e.g., U.S. Pat. No. 2,314,145 (1943) for a description of a tool for removing such weights, the conventional method for installing such weights has improved little over past years. That technique is, essentially, to first determine the optimum sizes and locations of weights to be placed on the wheel rim by dynamic, computer controlled, inertial, high speed, sophisticated, tire rotational apparatus, following which the technician holds the appropriate weight at the designated location on the tire rim with his thumb and fingers and whacks it with a hammer. If missed, as is too often the case, the technician suffers.
The present invention obviates many, indeed most, of the problems inherent in such tire balancing methods, and provides a convenient tool for installing, quickly, efficiently, accurately and painlessly, such wheel weights.
A holding and driving impact tool for installing wheel weights onto rims of automotive wheels at designated circumferential rim locations is provided. The tool includes an elongate housing having a first end and a second end, the housing containing therein a spring-loaded piston assembly which extends from the first end, through the center of the housing, to and through the second end and extending externally thereof to expose the head of the piston externally of the second end. The piston extends to the first end of the housing and there at is in adjacent proximity to magnetic holding means which are affixed to the housing at the first end. The magnetic holding means are capable of holding any one of the variety of wheel balance weights in present use in the balancing of pneumatic auto and truck tires.
In the preferred embodiment, the first end of the housing is shaped substantially in the form of axe2x80x9cVxe2x80x9d, and the magnetic holding means comprises a magnet embedded within the first end of the housing within one arm of thexe2x80x9cVxe2x80x9d and is flush with the surface of the arm of thexe2x80x9cVxe2x80x9d.
The piston assembly is preferably removably installed within the housing and affixed therein by means of snap ring and groove means proximate the second end of the housing. The tool housing may be generally cylindrical in shape and may have a knurled external surface thereof to provide enhanced gripping capability. The housing may have one or more flat surfaces formed in proximity to the first end thereof, for enhanced visibility of the balance weights, and the housing may have one or more longitudinal guide lines imprinted thereon proximate the first end, to enhance guiding the tool during impaction.